CVE-2000-0956 in Cyrus-SASL
Summary
by MITRE
cyrus-sasl before 1.5.24 in Red Hat Linux 7.0 does not properly verify the authorization for a local user, which could allow the users to bypass specified access restrictions.
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Analysis
by VulDB Data Team • 05/28/2018
The vulnerability described in CVE-2000-0956 affects the cyrus-sasl library version 1.5.23 and earlier, which was included in Red Hat Linux 7.0. This security flaw resides within the Simple Authentication and Security Layer implementation that governs how authentication mechanisms operate within network services. The issue specifically pertains to the authorization verification process for local users, creating a potential pathway for privilege escalation and unauthorized access to protected resources. The vulnerability represents a critical weakness in the authentication framework that could undermine the security posture of systems relying on this library for secure authentication services.
The technical flaw manifests in the improper validation of authorization contexts when local users attempt to access restricted services. The cyrus-sasl implementation fails to adequately verify that a user possesses the necessary permissions to access specific resources, allowing authenticated users to potentially bypass access controls that should restrict their capabilities. This weakness stems from insufficient authorization checking mechanisms within the library's authentication flow, where the system accepts user credentials without properly validating whether the authenticated user should have access to the requested resource or service. The flaw essentially creates a scenario where legitimate authentication does not guarantee proper authorization, opening the door for users to access resources beyond their intended privileges.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it could enable attackers to escalate privileges within systems that depend on cyrus-sasl for authentication. Local users who have authenticated to services using this library could potentially access restricted system functions, files, or network resources that should only be available to specific authorized users or groups. This weakness could be particularly damaging in environments where multiple users share system resources and where proper access controls are essential for maintaining system integrity and data confidentiality. The vulnerability affects the fundamental security model of authentication systems that rely on cyrus-sasl, potentially allowing for unauthorized data access or system manipulation.
Security professionals should implement immediate mitigations including upgrading to cyrus-sasl version 1.5.24 or later, which contains the necessary patches to address the authorization verification flaw. System administrators should also review and audit existing access control policies to identify any potential unauthorized access that may have occurred due to this vulnerability. The mitigation strategy should include comprehensive testing of authentication mechanisms to ensure proper authorization enforcement. Organizations should consider implementing additional monitoring and logging of authentication events to detect any suspicious activity that might indicate exploitation of this vulnerability. This vulnerability aligns with CWE-284, which describes improper access control, and could be leveraged by threat actors following techniques outlined in the ATT&CK framework under privilege escalation and credential access domains.
The broader implications of this vulnerability highlight the critical importance of proper authorization verification in authentication systems. The flaw demonstrates how weaknesses in the authorization phase of authentication can undermine even properly functioning authentication mechanisms. Organizations relying on similar libraries or authentication frameworks should conduct thorough security assessments to identify potential authorization bypass vulnerabilities. This case underscores the necessity of comprehensive security testing that covers both authentication and authorization phases, as the failure in either area can compromise overall system security. The vulnerability serves as a reminder that secure authentication systems require robust implementation of both credential verification and access control mechanisms to prevent unauthorized system access and privilege escalation.